After a cagey start from both sides, the hosts took the lead in emphatic fashion 17 minutes into the game.
Things would get even better for the Hatters as Daniel Bentley's mistake gifted the ball to Andy Drury just after the half-hour mark. The veteran midfielder then set up Mark Cullen, who tucked the ball home with little difficulty.
Southend started the second half on the front foot, as Barry Corr dragged a shot wide five minutes after the restart. Before long, the game had opened up, with both sides trading shots and playing end-to-end football.
Nevertheless, Luton were able to weather the storm, and could have added to their goal tally with promising efforts from Drury and Luke Wilkinson.
Ultimately the hosts were able to see the game out, despite Conor Clifford's threatening late chance.